Fill it with water from a bucket or hose prior to starting it.
No, you do not have to prime the oil pump.
you dont need to prime the pump
To prime the oil pump on most cars all you need to do is turn the motor over without it firing, disconnect the coil and turn the key, this will prime the pump.
You do not have to prime the pump. Just add the correct amount of oil and start the engine.
You do not have to prime it. It is self priming.
pump can.
A dry prime pump will work similar to a normal vacuum. However, the dry prime pump will suck up any solids, liquids, and will get rid of larger messes in a shorter amount of time.
Did you "RE-PRIME" the pump after you changed the pressure control switch? A likely reason you are not getting water would be that the pump "PRIME" was lost when you changed the pressure control switch. Pump seals can be burned up quickly if you run a jet well pump with no prime (lost prime) and will cause them to leak around pump shaft.
The fuel pump requires no priming.
How do you prime the oil pump on a 1986 Toyota truck with 20r/22r engine
The pump.
There is no reason to prime a fuel pump. If it is a electric pump, then just cycle the key a few times, It primes it's self. If it is a manual pump then just crank the engine until it picks up the fuel.